Technical Field
The present disclosure generally relates to systems and methods of removing pollutants from gases and more particularly to an exhaust gas scrubber for removing SOx, NOx, and CO2 from an exhaust gas stream.
Description of the Related Art
Ships are one of the most important modes of freight transportation in the world. Ships, although incredibly environmentally friendly compared to other transportation methods, including trucking and air freight, contribute to environmental pollution, including the introduction of sulfur dioxide (SO2), particulate matter (PM), nitrogen oxide (NOx) and carbon dioxide (CO2). These pollutants contribute to global warming, ozone depletion, ground level ozone formation and acidification. As international commerce expands, so does the environmental impact of increased shipping traffic on the world's oceans.
Exhaust gas scrubbers, in particular those that reduce the emissions of sulfur oxides, including sulfur dioxide, use chemicals, such as lime, sodium hydroxide, and sodium sulfite, among others, to remove sulfur from exhaust gas streams. Using these chemicals comes with its own burdens, including handling, storage, cost, and disposal. In addition, in many cases, the effluent from the process fluids that are used in these scrubbers cannot be disposed of in the ocean due to environmental restrictions on the disposal of such chemicals.